assertEquals("", Strings.commonPrefix("abc", ""));
    assertEquals("", Strings.commonPrefix("", "abc"));
    assertEquals("", Strings.commonPrefix("abcde", "xyz"));
    assertEquals("", Strings.commonPrefix("xyz", "abcde"));
    assertEquals("", Strings.commonPrefix("xyz", "abcxyz"));
    assertEquals("a", Strings.commonPrefix("abc", "aaaaa"));
    assertEquals("aa", Strings.commonPrefix("aa", "aaaaa"));

}

type badConfigErr struct {
	Err error
}

// Error - return the error message
func (bce badConfigErr) Error() string {
	return bce.Err.Error()
}

// Unwrap the error to its underlying error.
func (bce badConfigErr) Unwrap() error {
	return bce.Err
}

type setConfigResult struct {
	Cfg                     config.Config
	SubSys                  string

			keys:     []string{"etag", "md5"},
			want:     map[string]string{"content-type": "application/octet-stream", "x-amz-storage-class": "STANDARD"},
		},
		{
			name:     "2",
			metadata: map[string]string{"content-type": "application/octet-stream", "etag": "de75a98baf2c6aef435b57dd0fc33c86", "x-amz-storage-class": "REDUCED_REDUNDANCY", "md5sum": "abcde"},
			keys:     []string{"etag", "md5sum"},

    builder.append("C");
    assertEquals("C", iterator.next());
    assertFalse(iterator.hasNext());
  }

  public void testFixedLengthSimpleSplit() {
    String simple = "abcde";
    Iterable<String> letters = Splitter.fixedLength(2).split(simple);
    assertThat(letters).containsExactly("ab", "cd", "e").inOrder();
  }

  public void testFixedLengthSplitEqualChunkLength() {

    builder.append("C");
    assertEquals("C", iterator.next());
    assertFalse(iterator.hasNext());
  }

  public void testFixedLengthSimpleSplit() {
    String simple = "abcde";
    Iterable<String> letters = Splitter.fixedLength(2).split(simple);
    assertThat(letters).containsExactly("ab", "cd", "e").inOrder();
  }

  public void testFixedLengthSplitEqualChunkLength() {

  }

  public void testConcat() throws IOException {
    CharSource c1 = CharSource.wrap("abc");
    CharSource c2 = CharSource.wrap("");
    CharSource c3 = CharSource.wrap("de");

    String expected = "abcde";

    assertEquals(expected, CharSource.concat(ImmutableList.of(c1, c2, c3)).read());
    assertEquals(expected, CharSource.concat(c1, c2, c3).read());

  }

  public void testConcat() throws IOException {
    CharSource c1 = CharSource.wrap("abc");
    CharSource c2 = CharSource.wrap("");
    CharSource c3 = CharSource.wrap("de");

    String expected = "abcde";

    assertEquals(expected, CharSource.concat(ImmutableList.of(c1, c2, c3)).read());
    assertEquals(expected, CharSource.concat(c1, c2, c3).read());

    assertEquals(2, CharStreams.readLines(r, conditional).intValue());
    assertEquals("ab", sb.toString());
  }

  public void testSkipFully_EOF() throws IOException {
    Reader reader = new StringReader("abcde");
    assertThrows(EOFException.class, () -> CharStreams.skipFully(reader, 6));
  }

  public void testSkipFully() throws IOException {
    String testString = "abcdef";

    assertEquals(2, CharStreams.readLines(r, conditional).intValue());
    assertEquals("ab", sb.toString());
  }

  public void testSkipFully_EOF() throws IOException {
    Reader reader = new StringReader("abcde");
    assertThrows(EOFException.class, () -> CharStreams.skipFully(reader, 6));
  }

  public void testSkipFully() throws IOException {
    String testString = "abcdef";

    return onPatternInternal(Platform.compilePattern(separatorPattern));
  }

  /**
   * Returns a splitter that divides strings into pieces of the given length. For example, {@code
   * Splitter.fixedLength(2).split("abcde")} returns an iterable containing {@code ["ab", "cd",
   * "e"]}. The last piece can be smaller than {@code length} but will never be empty.
   *